This invention relates to an improved dual flush valve assembly for a toilet tank. More particularly, the invention relates to a valve assembly, the construction of which includes a hollow body provided with a pair of pivotally mounted lever arms actuating a pair of valves adapted for causing a partial or full discharge of water from the tank through an opening in the bottom wall thereof.
As is well known, a severe water shortage exists in the United States, particularly in the State of California, due to continued statewide draught. As a result, mandatory water conservation programs have been established in many areas, such programs including penalties assessed for excessive water usage. Although various measures attempting to utilize water more efficiently and thus reduce its overall consumption have been suggested, the total amount of water used still remains much too high. Moreover, it is projected that water shortage may become more acute in the future.
In an attempt to at least partially alleviate this situation, certain water-saving devices for toilet tanks have been proposed and described in the patent literature. For example, U.S. Pat. No. 2,731,647 to Groth et al. describes a dual type flush valve device comprising a pair of vertically disposed valves actuated by a handle movable in clockwise and counterclockwise directions. U.S. Pat. No. 3,375,531 to Lake discloses a device having a pair of transversely disposed valves, each valve connected to a separate flush handle. U.S. Pat. No. 3,758,893 to Smolinski teaches a toilet flush system for providing light or heavy flushes by twisting a selector clockwise or pressing it inwardly. U.S. Pat. No. 3,768,103 to Robluson describes a toilet flush valve assembly comprising a pair of valves mounted on an upstanding straight length water discharge pipe also functioning as an overflow pipe. U.S. Pat. No. 3,795,016 to Eastman teaches a toilet water tank having two valves operable by two actuator arms, each arm coupled with a separate handle. U.S. Pat. No. 3,918,105 to Young describes two inlets in a toilet tank which are closable by hydraulically operated lids. U.S. Pat. No. 4,042,982 to Contreras discloses a toilet flush valve assembly having two intersecting conduits, each connected with a valve assembly which prevents cross-flow of water from one conduit through the other conduit. U.S. Pat. No. 4,096,591 to Awis teaches a dual flush valve system operable by a flush handle rotatable in opposite directions. U.S. Pat. No. 4,110,850 to Tadei describes a flush valve assembly having a pair of valves actuated by two separate handles. U.S. Pat. No. 4,122,564 to Addicks et al. shows a dual flush valve system operated by a handle rotatable in clockwise and counterclockwise directions. U.S. Pat. No. 4,504,984 to Burns describes a two-stage toilet flush valve assembly comprising a single flush lever connected to both valves; and U.S. Pat. No. 4,829,605 to Agostino discloses a system having two valves and two arms connected to two separate handles.
While the aforementioned patents disclose the general concept of various toilet flush mechanisms having different structures, the valve assembly of the present invention provides a new approach to the structure thereof which offers certain advantages over the prior art devices.